Means for connecting multiconductor cables



May 8, 1962 c. R. CURTIS MEANS FOR CONNECTING MULTI-CONDUCTOR CABLES Filed Feb. 9, 1959 4 Sheets-Sheet 1 y 1 c. R. CURTIS 3,034,089

MEANS FOR CONNECTING MULTI-CONDUCTOR CABLES Filed Feb. 9, 1959 4 Sheets-Sheet 2 May 8, 1962 c. R. CURTIS- ,03

MEANS FOR CONNECTING MULTI-CONDUCTOR CABLES Filed Feb. 9, 1959 4 Sheets-Sheet 3 May 8, 1962 c. R. CURTIS MEANS FOR CONNECTING MULTI-CONDUCTOR CABLES Filed Feb. 9, 1.959

4 Sheets-Sheet 4 United states Patent This invention relates in general to a separable electrical connector for multi-conductor cables, and more particularly to a contact assembly for such connectors which includes a pair of panels for carrying the connecting elements, one of the panels typically being the outlet for an electrical device, such as a computer, and the other being secured in a portable housing adapted to be coupled by actuation of a connecting mechanism to the device outlet.

As design desiderata, the contact assembly of such a connector electrically should provide a stable and absolutely reliable contact over a wide temperature range for high and low voltage level circuits with a negligible noise introduction factor, and mechanically should have a long life under hard usage while being simple, inexpensive, easy to disassemble and reassemble without the use of tooling, with the component parts for the mating sections being reversible and interchangeable to reduce the number of dilierent parts to a minimum. Overall, the connector should have no critical tolerances, but the parts should interfit with precision while being simple and foolproof in operation.

A wide variety ofconnectors are available in the art, but all in more or less respects fail to provide the desired characteristics.

The principal advantage of the present invention is the provision of components by which the aforesaid design desiderata maybe united in one construction of a multicontact connector.

The embodiment to be described as illustrative of-the present invention is also advantageous in that the operating mechanism and associated panel are housed in a portable unit which may be coupled, with or without the contact elements being engaged, to a similar panel mounted either on a stationary electrical device or in another portableunit, the contact coupling action smoothly bringing the contact elements in the sets into engagement simultaneously.

Other advantages and attainments of thepresent inven= tion will become apparent to those skilled in the art upon an examination of the drawings and the following detailed specification which show and describe a preferred embodiment; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting on the invention but, on the contrary, is given for pur poses of illustration in order that others skilled'in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify and adapt it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

FIGURE 1:: and FIGURE lb are perspective views of an embodiment of a separable connector assembly according to the present invention, the pair of units constituting the assembly being separated but in alignment ready to be connected;

FIGURE 2 is a perspective view illustrating the housing shell for the connector unit of FIGURE 1b;

FIGURE 3 illustrates in perspective'a stand-off element carried within the housing shell;

FIGURE 4 is a sectional side view of the connector taken substantially along the center line of FIGURE 1, but with the units being in closed interconnected position and certain parts being shown in elevation for purposes of illustration; 1

FIGURE 5 is a view similar to FIGURE 4, but with the connector units operatively partly disconnected; FIGURE 6 is a View similar to FIGURE 4, but with the connectors units operatively fully disconnected and ready for separation, parts being broken away for the sake of clarity;

FIGURE 7 is a sectional view along lines 7-7 of FIGURE 4;

FIGURE 8 is an exploded view of the actuating lever 315d cam arrangement of the connector unit of FIGURE 1 FIGURE 9 is a fragmentary sectionalview on an enlarged scale of the contact elements and supporting panels when the connector units are closed as in FIGURE 4;

FIGURE 10 is a view similar to FIGURE 9, but taken when the connector units are disposed as in-FIGURE 5;

FIGURE 11 is a sectional view taken along lines 1111 of FIGURE 9;

FIGURE 12 is a planview of a strip of the contact ele-. ments as they may be formed in a progressive die;

FIGURE 13, is a perspective view of a panel element carried by either one of the units of the connector assemy;

FIGURE 14 is a perspective view showing the opposite side of a panel element similar to that of FIGURE 13;

FIGURE 15 is a perspective view of a bracket for mounting a panel element in the connector unit of FIG- URE la;

FIGURE 16 is a plan view of the strain relief assembly for introducing a cable into the connector unit of FIG- U'RE lb;

FIGURE 17 is a side view, partly in section and partly broken away for clarity, of the strain relief assembly; and

FIGURE 18 is a perspective view of a grommet or packing element carried within the strain relief assembly.

In the drawings the illustrative embodiment of the separable connector assembly of the present invention in general includes a pair of units A and B adapted to be brought operatively together to complete a multiplicity of circuit paths through the assembly, unit A being set for example in the control board or some convenient portion in the housing 2, fragmentarily shown in FIGURE 1a, of a computing, printing or accounting machine or similar device, and constituting the electrical coupling into the internal electrical circuitry of the device. Unit B comprises a portable coupling mechanism serving to support and connect selectively the various wires of an external cable 4 to the appropriate wires brought to unit A.

With general reference to FIGURES 9-11, units A and B each include a panel 6a and 6b carrying, preferably by a releasable snap-fit arrangement in apertures 8a and 8b, cooperating sets of contact elements 10a and 10b which terminate the respective sets of conductor wires 12a and 12b to be electrically coupled when the units are operatively brought together. It will be appreciated that each assembly of an A and B unit may accommodate as many connections as desired, a typical embodiment providing 200 circuit connections, while there additionally may be incorporated in a particular electrical installation several A units to which any one or more of several B units may be joined. Further, it is contemplated that the pair of panel and contact connector elements may alone comprise the units of the assembly according to the requirements of a particular use, all as will become apparent from the following detailed description.

Certain of the parts comprising units A and B of the illustrated embodiment are advantageously of identical construction and character. In the description and drawings such parts are designated by a given reference numeral when referred to in general, an a or"b being ap pended to the numeral to indicate their incorporation in either unit A or unit B respectively.

For achieving simplicity in fabrication and assembly panels 611 and 6b advantageously are identical and of relatively hard, molded insulation material, and of generally square configuration. The contact receiving apertures 8, FIGURES 13 and 14, usually in rows and columns, extend through the flat main body portion 14 of the panels, each aperture preferably having locator indicia, such as a number not shown, formed during molding of the panel. As best shown in FIGURES 9 to 11, the passageway defined by each aperture is essentially rectangular and extends straight through the panel body except that one wall symmetrically converges inwardly thereof at a slight angle of inclination from both faces of the panel to present a central portion 15 of reduced cross-section, exemplary wall portions 16a and 18a of panel 6a each extending approximately one-third the passageway length and inclined at an angle of approximately 15 for purposes to be explained. A flange or hood 20 projects outwardly from one face of the panel brim. A channel 22 extending around body 14 within flange 20 is congruous with a bead 24 raised outwardly from the other face of the panel whereby .When two panels are properly brought together the bead 24a of one is guided by flange 20b in loose interfitting relation into groove 22b of the other, FIGURES 4 to 7, for as suring aligned and substantially parallel planar relative movement of the panels. For axially polarizing the panels, on each inside wall of flange 20 is a pair of bosses 26 which are in alignment with a pair of recesses 28 on the outside wall of bead 24, the spacing of the various pairs of bosses being different so that they will interfere with the admission of bead 24 into groove 22 unless the panels are oriented to bring the desired pairs of apertures 8a and 8b into opposition.

Centrally of body 14 is a generally square aperture 30 from the corners of which inwardly project integral lugs 32 inset from both faces of the panel for flush mountingon either panel side a keeper plate 34, as by threaded bolts 36 inserted through bolt holes 38 in lugs 32 and cooperating with suitably threaded bolt holes 40 in plate 34, FIGURES 1a and 7. Lugs 32 and bolt holes 38 and 4 are symmetrically arranged so that keeper plate 34 may be clamped to the desired panel face in any one of four possible axial orientations for polarization purposes to be made apparent. A short slot 42 and a long slot 44, best shown at 42a and 44a in FIGURE 1a, extend inwardly from an edge in opposed offset relation to the vertica center line of keeper plate 34, the bottom lip of slot 42a providing a seat for a notch 46 in the offset end 48 of latch 50 pivotally mounted in housing 52 of unit B. Latch 50, preferably stamped from suitable flat sheet metal stock, at its end 48 projects through slot 44b of keeper plate 34b and is adapted to be inserted in slot 42a of keeper plate 34a, FIGURES 4 to 7, upon coupling of the assembly units, the longer length of slot 44b permitting sufi'icient travel of latch end 48 therein to seat notch 46 fully over the bottom edge of shorter slot 42a, FIGURE 4.

For mounting the panels in assembly units A and B, a rib 54 extends around the panel periphery from substantially the mid-point of the panel thickness, except for discontinuities at each of the panel corners. lFlange 20 is reduced in thickness at the panel corners to define with rib 54 shoulders 56, FIGURES 13 and 14. In unit A rib 54a is received in groove 58 of a frame or bracket 60, FIG- URES 4-7, adapted to be aflixed to machine housing 2, as by bolts 62 in FIGURE la, which frame for convenience in assembly preferably is segmented, for example, in four similar corner segments, one segment 64 being shown in FIGURE 15 and in phantom in position on panel 6 in FIGURE 14. Each segment 64 carries a semi-cylindrical guide block 66 curved to fit between shoulder 56 around the panel corners and of a length to upstand well above the panel face. a

In unit B housing 52, which may be a shell cast of a suitable metal such as zinc or a lightweight aluminum alloy, is open at one side to slightly greater dimensions than those of the panel whereby to receive panel 6b, FIGURES 4 to 7. The ends of a series of integral ribs 68 provide stops against which the sides of rib54ib abut for positioning the outside panel face substantially flush with the edges 70 defining the housing opening. Approximately centrally of housing 52 is a reentrant hollow standard 72 terminating in an internally threaded spindle 74 in alignment with bolt hole 76b of keeper plate 34b so that bolt 7 8 passed therethrough into spindle 7 4 serves to clamp panel 6b rigidly in the housing. If desired a cylindrical spacer 80 may be interposed between spindle 74 and keeper plate 34b.

From the foregoing it should berobserved that a panel 6 may be set in either of units A or B with either panel face exposed. Thus, a particular setting of panel 611 in unit A, such as is shown in FIGURE 1a with bead 24a facing outwardly of the associated machine housing 2 and keeper plate 34a set in one of its four possible orientations relative to polarizing recesses 28, fixes the setting of panel 6b in unit B in one of eight possible positions for the units to engage. Otherwise, for the setting shown, either bead 24b will abut bead 24a or the axial orientation of unit B and panel 6b required to mate polarizing bosses 26 in recesses 24 will find slot 42a misaligned with latch end 48, thereby interfering with and preventing coupling of the assembly. Accordingly, in an installation requiring several separable connectors it has been made possible to assure to at least eight combinations that no other than the desired unit B will be coupled to a given unit A.

Referring now to FIGURES 9 to 12, contact elements 10 are shown in detail. To admit of panel reversibility while retaining the wiring flexibility of snap-in inserts, contact elements 10 are constructed to be insertable or released from either face of the panels advantageously without the use of tools. Again, for simplicity in fabrication and assembly the contact inserts are of single, hermaphrodite design and of suitable resilient metal, preferably of sheet stock so as to be capable of fabrication by progressive die-stamping techniques as exemplified by the progressively partly formed blanks 10, I0", 10", etc. depending between carrier strips 82 in ladder array in FIGURE 12. After formation a series of completed, preformed blanks 10 conveniently may be handled in reels for feeding to automatic or semi-automatic terminal applying machines, typified by Handel Patent No. 2,705,797 issued April 12, 1955, which detaches the individual contact inserts from the strip and affixes them to conductor wires 12 presented to the machine, preferably by solderless cold-forging or crimping methods well known in the art, see Macy Patent No. 2,600,012.

To these purposes contact inserts 10 each include a base portion 84 from the rear end of which longitudinally extends a wire barrel portion 86 for crimping on the metal core of wire 12 and, if desired, an insulation support barrel portion 88 for gripping the insulation of wire 12, the barrel portions being formed from laterally ex tending pairs of ears defining wire receiving troughs conventional in the art. Upstanding from opposite sides of base 84 to a greater height than the height of reduced section 15 of the apertures, FIGURE 11, are a pair of resiliently supported wings 90 and 92, the free ends thereof being bent toward one another to overlie base 84 to provide pressure plates 94 and 96 which are canted downwardly toward the forward end of base 84 at an angle approximately the same as the slope of inclined wall portions 16 and 18. From the forward edge of plate 96 extends an elongated spring arm 98 at approximately the same angle of inclination toward base 84 to bias downwardly toward the base plane a contact finger 100 which is generally parallel to but ofiset from the longitudinal axis of the insert contact finger 100 provides the means for electrically engaging under spring pressure the opposed contact insert in the opposite panel,

the spring arm being a length to project the contact finger outwardly of. the panel carrying it. Extending from the forward end of base is a contact plate Hi2 in oftset relation to the longitudinal axis of the insert and in opposition to contact finger ltlil so as to be engaged by the opposed contact finger of the mating insert when the panels are brought together. The free end of plate 102 is turned down to provide a latching detent 1G4 arrangedto snap over the edge of the aperture for retaining the insert in the panel. The widthof the contact insert, taken at finger 1% and plate Hi2, ap, roxirnates the width of the aperture passageway to provide a lateral snug fit.

It will be observed that in the symmetry of the aperture passageway, two pairs of symmetrically related stop shoulders are provided, i.e. either wall portion in or 1% taken with the face of the panel at the remote end of the aperture, whereby the contact elements may be inerted from either side of the panel. Accordingly, on introducing the contact insert into a, panel aperture, pressure. plates 94 and 96 will first engage sloping wall portions 16 and 18.

As the insertion force is increased, pressure plates 94 and 96 will be resiliently canted downwardly into ap. proximate conformance with the inclination of wall portion'lo or 18, increasing the downward bias of spring arm 98 while pressing base 34 and detent 1M firmly against the aperture bottom wall until detent the snaps in place Over the aperture edge, pressure plate 94 serving to balance the. forces on the insert for stabilization purposes. The reaction of pressure plates 94 and 96 on Wall portion 16' or 18 provides a back bias firmly anchoring the contact insert in position that advantageously imparts a slight backward kick to the insert in aid of its release when detent 164- is raised above the aperture edge, whereupon the insert may be withdrawn by wire In some conditions of use it is desirable that detent 104 be effective to retain the insert in the panel up to relatively high tensile stresses applied to wires 12. To enhance the detent action, the end portion 194 of the contact plate may be reversely bent somewhat more than. 90, as shown to latch behind a boss 1% formed adjacent each of the aperture edges.

With each contact 1% seated in one direction in apertures 8a in panel 6a and each contact ltlb seated in reverse direction in apertures 8b of panel 6b, alignment of the apertures brings contact fingers lt'lila and 1001) respectively into alignment with contact plates 3102b and 1tl2a, FIGURE 10, whereupon direct axial movement of'the panels toward one another causes the projecting contact fingers to enter into the opposed apertures and to. engage and slide on the contact plates under the spring pressure of spring arms 8a and 98b, FIGURES 9 and 11, the tips 196a and 1661) of the contact fingers being curved upwardly to provide a ramp for camrning the fingers onto the surface of the contact plates.

To improve the Wear resistant qualities of the sliding contact the forward half of each contact plate 102 may be bent downwardly, for example at a 20 angle relative to the plane of base 84, so that on setting the insert in the panel contact plate 1632. will present a ramp 1W7 inclined relative to the axis of the panel. On axial movement of the panels, curved tips 1% may be arranged to strike ramp 107 intermediate its length thus affording a relatively large area of initial contact and a sliding contact of gradually increasing contact pressure. In addition the inclined relation of the final position of each contact produces a. small axial component of force, reversely directed, the combined back pressure of all the contacts being sufiicient to take up any slack or wear, in the mechanical system of the connector.

To protect the exposed, projecting contact fingers 100 when the assembly units are separated, flange 20 and bead 24 preferably are raised farther, relative to the panel faces,,than the projection of the contact fingers.

The dual path of contact and frictional engagement thus provided each pair of wires 12a and 12b by the terminal contact inserts obviously enhances the connec tion reliability therebetween, for example, when one path corrodes, or becomes pitted, etc. the other may yet function. Contact reliability may be further enhanced by plating the base metal of the inserts with gold, silver, or the like, especially when low voltage signals are to be transmitted.

To increase the quality of the electrical contact between the contact inserts further, it is desired that in the coupling of the assembly the ultimate areas of engagement of fingers on plates 102 be automatically prewiped to cleanse the contact areas of any foreign matter. To this end the assembly includes a rotary-to-reciprocating motion transmitting mechanism which, in the coupling or connecting throw of an operating lever, first moves the panels axially toward one another to cause contact fingers 100 to engage and traverse under pressure defined paths of contact longitudinally along the associated contact plates 1&2, thus prewiping or scrubbing the contact plates, and then axially separates the panels to a predetermined distance causing the contact fingers to be partly withdrawn along the paths of contact on plates 102 to place the ultimate areas of engagement at an intermediate point of the contact paths.

In the illustrated embodiment the rotary-to-reciprocating motion transmitting and coupling mechanism is mounted in unit B, as best shown in FIGURES 1b, 2 and 4 to 8, and includes latch '50, a circular opening 1ll8 therein remote from oflset end 43 receiving in pivotal relation a cylindrical cam block 11! which is eccentrically supported for rotation between opposed external walls 112 of housing 52 on a pin 114 force fitted in transversely aligned holes 116 in the rear portion of the housing. Latch 59 is admitted into the interior of housing 52 through a slot 118' in standard 72 for projection through keeper plate 34b and ultimate engagement with keeper plate 34a, and is biased, clockwise in FIGURES 4 through 6, by a tension spring 120 fixed at one end to housing 52 and at the other end to the latch, to urge its end 48 downwardly to seat notch 46 on the lower edge of slot 42a. Eccentric cam 11% is rotated by operating lever 122 which is provided with a bracket 124 having a cylindrical bore 126. for receiving the cam block, and bifurcated for receiving between the leaves thereof and stabilizing the pivotal end of latch Stl. Flat pins 128 inserted in appropriate slots serve to key cam 11b for rotation with lever 122, the end of which may be enlarged to provide an operating handle 130.

As indicated in FIGURES 4 and 6, lever 122 is rotatable over approximately l8ll between housing stop 132 defining the closed position of the assembly, FIGURE 4, and stop 134 in the decoupling of the assembly, FIGURE 6. In moving between these stops lever 122 is arranged to rotate the high point of cam from a position between but below the center line of pin 114 and the bottom edge of slot 42a, FIGURE 6, clockwise to a position above and beyond the center line, FIGURE 4, thereby relatively reciprocating latch Stl from a maximum extended position, to the right in FIGURE 6, through a maximum retracted position Where the high point of the cam passes the center line, to an intermediate forward position.

In operation unit B is manually brought in alignment with unit A, FIGURES la and lb, except that handle 13d is down adjacent stopl34, and then is moved forwardly causing guide blocks 66 relatively to enter housing 52 between shoulders 56b of panel 6b, guide blocks 66 preferably being beveled for easy entry. Should the panels be properly polarized, unit B may then he slid on guide blocks 66 until latch end 48 enters slot 42:: and notch 46 clicks into position, the nose of latch end 48 being beveled so that latch 50 may be cammed upwardly "Z against the tension of spring 120 as the nose passes over the bottom edge of the slot. As now disposed, generally as indicated in FIGURE 5, head 24a has partly entered channel 22b assuring precise opposition of apertures 8n and 8b, but the panels are separated suificiently far that the contact elements are not yet interengaged, see FIG URE 10. Rotating handle 136 and cam block 116 now tends to shift latch 54] rearwardly, to the left in FIGURES and 6, however the latch is relatively med in position by virtue of its coupling to keeper plate 42a of panel 6a. The reaction of rotating the cam. block first forces housing 52 and panel 6b through pin 114 toward panel 611, simultaneously engaging the contact elements, until the cam high point arrives at the center line as described. Thereafter, until stop 132 is reached, continued rotation of handle 130 effects the desired partial separation of the panels and the resultant partial retracing of the paths of contact between the contact elements, FIGURE 9.

Under certain conditions it will be desirable to have the units electrically disconnected but mechanically coupled. In this event the units are left, either in the coupling or decoupling stroke of the operating lever, approximately in the position as shown in FIGURE 5 where latch 56 retains the units together, the weight of unit B- being borne by guide blocks 66, while the contact elements are disengaged, see FIGURE 10.

To decouple the contacts and separate the assembly it is necessary only to rotate handle 130 counterclockwise, thereby reversing the coupling action except that, in the final few degrees of throw, the end 136 of lever 122 is arranged to engage the kick latch 50 upwardly. FIGURE 6, to unseat notch 46 from keeper plate 34a whereupon unit B may be detached. In this connection in order to avoid undue stress being applied through latch 50 to keeper plate 34:: and lugs 32a in decoupling the units against the combined frictional loading of the contact elements, and further to balance the applied retractile force and assure axial separation of the panels, auxiliary retraction means are preferably provided. For this purpose in the illustrative embodiment a pair of stand ofi? plates 138 are slidably mounted in either side of housing 52, each plate having an inturned end forming a bearing 140 slidably guided on a pin 142 which may be integrally cast with the housing and extends forwardly therein adjacent the base of standard 72. Bearings 140 are admitted through the side of standard 72 by openings 144 and are disposed immediately forward in parallel overlapping relation to bracket 124 which has a cylindrical surface eccentrically disposed relative to pin 114 for camming the bearings forwardly in the decoupling throw of lever 122 similar to the action of cam block 110 and latch 50.

Stand ofif plates 138 each terminate forwardly in a pair of spaced fingers 146 disposed in the corners of housing 52 so as to be in alignment with the end faces of guide blocks 66 when the units are assembled. Camming bearings 14!) forwardly during decoupling of the assembly results in fingers 146 forcefully abutting guide blocks 66 as best shown in FIGURE 6, the reaction imparting a rearward thrust on the housing 52 through pin 114 as desired. Stand off plates 138 may be further guided for movement by ribs 148, FIGURE 2, providing channels in the housing in which the side edges of the plates adjacent fingers 146 are adapted to ride.

Fingers 146 also are arranged to abut under pressure guide blocks 66 when the units are fully coupled to cooperate with latch 50 in assuring that portable unit B will be sustained in a mechanically stable position rela tive to unit A.

Cable 4 is preferably introduced into housing 52 by means which relieves the contact inserts terminating the individual wires from the stress imposed by the cable weight. With particular reference to FIGURES 16 to 18 in conjunction with FIGURES 2 and 4 to 7, heads 150 define a segmented channel 152 adjacent a generally U- shaped opening in the bottom wall of housing 52.

Flanges 154 of bottom cover plate 156 are slidable in channels 152 for locating the cover plate substantially flush in the bottom opening of the housing. Rib 157 on the inner side of plate 156' is disposed so as to be engaged by rib 54b when panel 6b is clamped in place for securing plate 1'56 and the strain relief assembly in position in the housing. Integral with plate 156 is an apertured Well 158 through which cable 4 is passed into housing 52, the conical bottom 16d of the well providing a seat for annular packing 162 of rubber or similar resilient material. A gland 164 slidably received in well 158 is adapted to be driven against packing 162 by bolts 166 extending through the well and threaded into the gland thereby to squeeze and extrude the packing inwardly against cable 4 for strain relief support, the bearing surfaces 16% of the gland being conical in mirror image of well bottom 160.

FIGURE 18 illustrates in detail packing 162 which is generally triangular in cross-section. A series of equally spaced radial slots 170 terminating just short of the cylindrical inside surface render the packing more flexible in use, and conveniently divide the packing into sections, more or less of which may be removed by severing through the thin inside wall according to the size of cable 4. In the event, on matching the inside packing diameter to a relatively small diameter cable in use, so many of the packing sections are removed that the conical bearing surfaces of gland 164 and well 158 do not adequately grip therebetween the sloping outside surfaces of the packing, conical adapter or take-up rings 172 may be positioned on either side of the packing as shown in FIGURE 17.

It will now be apparent that the present invention provides a separable electrical coupling device which is compact, of inexpensive construction while being simple and fool-proof in operation, yet capable of accommodating a large number of Wires to be joined in a manner whereby the circuit paths are easy and convenient to establish or revise. Furthermore, the assembly components are highly versatile in use, for example, under certain conditions only the pair of panels with the associated contact inserts may be employed, relying on means such as a nut and bolt, not shown, passed through bolt holes 76 of the keeper plates to hold the panels together. Alternatively, in other circumstances it may be desirable to couple a pair of the portable units B to which condition the assembly system is adapted. This may best be understood by reference to FIGURE 7, visualizing panel 6a to be incorporated in a portable unit such as unit B, the keeper plate slots 44a and 42b providing a path, parallel to and offset from latch end 48 of unit B, for the latch end of the second portable unit.

It will also be appreciated by those skilled in the art that the duplicate nature of many of the assembly components achieves a noncriticality in the overall tolerances hitherto impossible with previous devices of the type to which this invention relates. For example, panels 6 may be the product of a single mold assuring precise alignment of apertures 8a and 8b regardless of any irregularity in the spacing of apertures in any one panel. Relative to the seating of the contact inserts, any divergence from the precise dimensions desired simply adds to or lessens the back-bias on pressure plates 94 and 26.

I claim:

1. A sheet metal contact element for insertion in an apertured panel of an electrical connector, each aperture having an inclined wall facing the insertion end thereof, said contact element comprising a base portion, wire attaching means at the rear end of said base portion, a pressure plate inclined downwardly toward the forward end of said base portion for engaging the inclined aperture wall and stopping forward movement of said contact element on insertion thereof, means resiliently supporting said pressure plate, detent means arranged to engage complementary means of the panel as said pressure plate is pressed against the inclined aperture wall for stopping rearward movement of the contact element, and a contact plate and a spring biased contact finger longitudinally extending forwardly of said base portion in opposed offset relation thereto, said contact finger extendingbeyond the end of said contact plate for sliding frictional engagement with the contact plate of a similar contact element supported in reverse opposed relation.

2. A sheet metal'contact'element for insertion in an apertured panel of an *electricalconnector, each aperture having an inclined wall facing the insertion end thereof, said contact element-comprising-a base portion, wire attaching means at the rear-end of said base portion, a pressure plate inclined downwardly toward the forward end of said base portion for engaging the inclined aperture wall on insertion of said contact element in the aperture, means resiliently supporting said pressure plate, detent means for engaging complementary means of the panel as said pressure plate is pressed against the inclined aperture \wall to secure the contact element in the panel and a spring arm extending from the forward edge of and biased downwardly by said pressure plate, said spring arm terminating in a contact finger for engaging a cooperating contact element of the connector.

3. A sheet metal contact element for insertion in an apertured panel of an electrical connector, each aperture having an inclined wall facing the insertion end thereof, said contact element comprising a base portion, wire attaching means at the rear end of said base portion, a pressure plate inclined downwardly toward the forward end of said base portion for engaging the inclined aperture wall on insertion of said contact element in the aperture, means resiliently supporting said pressure plate, a contact plate longitudinally extending from said forward end in lateral offset relation to the axis of said base portion, detent means for engaging complementary means of the panel as said pressure plate is pressed against the inclined aperture wall to secure the contact element in the panel, and a spring arm extending from the forward edge of and biased downwardly by said pressure plate, said spring arm terminating in a contact finger longitudinally extending beyond and in opposed offset relation to said contact plate relative to said base portion for sliding frictional engagement with the contact plate of a similar contact element supported in reverse and opposed relation.

4. A sheet metal contact element for insertion in an apertured panel of an electrical connector, each aperture having an inclined wall facing the insertion end thereof, said contact element comprising a base portion, wire at taching means at the rear end of said base portion, a wing upstanding from one side of said base portion, the end portion of said wing being inturned to overlie and inclined downwardly toward the forward end of said base portion to define a pressure plate for engaging the inclined aperture wall, a contact plate longitudinally extending from said forward end in lateral offset relation to the axis of said base portion, detent means for engaging complementary means of the panel as said pressure plate is pressed against the inclined aperture wall to secure the contact element in the panel, and a spring arm extending from the forward edge of and biased downwardly by said pressure plate, said spring arm terminating in a contact finger longitudinally extending beyond and in opposed offset relation to said contact plate relative to said base portion for sliding frictional engagement with the contact plate of a similar contact element supported in reverse and opposed relation.

5. A sheet metal contact element for insertion in an apertured panel of an electrical connector, each aperture having an inclined wall facing the insertion end thereof, said contact element comprising a base portion, wire attaching means at the rear end of said base portion, a wing upstanding from one side of said base portion, the end portion of said wing being inturned to overlie and inclined downwardly toward the forward end of said base portion lfi to define a pressure plate for engaging the inclined aperture wall, a contact plate longitudinally extending from said forward end in lateral offset relation to the axis of said base portion, the end portion of said contact plate being turned downwardly to provide a detent arranged to snap over the forward edge of the aperture as said pressure plate is pressed against the inclined aperture wall on insertion of the contact element, and a spring arm extending from the forward edge of said pressure plate terminating in a contact finger longitudinally extending beyond and in opposed offset relation to said contact plate relative to said base portion for sliding frictional engagement with a contact plate of a similar contact element supported in reverse and opposed relation.

6. A sheet metal contact element for insertion in an apertured panel of an electrical connector, the apertures having an inclined wall facing the insertion end thereof, said contact element comprising a base portion, wire attaching means at the rear end of said base portion, a pair of wings upstanding from opposite sides of said base portion, the end portions of said wings being inturned toward one another to overlie and inclined downwardly toward the forward end of said base portion to define pressure plates for engaging the inclined aperture wall, a contact plate longitudinally extending from said forward end in lateral offset relation to the axis of said base portion, the end portion of said contact plate being turned downwardly to provide a detent arranged to snap over the forward edge of the aperture as said pressure plates are pressed against the inclined aperture wall on insertion of the contact element, and a spring arm extending from the forward edge of one of said pressure plates terminating in a contact finger longitudinally extending beyond and in opposed offset relation to said contact plate relative to said base portion for sliding frictional engagement with a contact plate of a similar contact element supported in reverse and opposed relation.

7. A contact assembly for a separable multi-contact connector comprising a pair of interengageable units; one of said units including a panel having a plurality of apertures and a set of contact elements inserted therein, one wall of each aperture symmetrically converging inwardly from the opposite faces of the panel to a reduced central section, each contact element including a resiliently supported pressure plate abutted against a converging side of said wall and a pair of longitudinally extending laterally offset spring arms, one of said spring arms defining a contact plate having detent means cooperating with a complementary portion of the panel to maintain said pressure plate in position, the other spring arm being biased by said pressure plate toward the plane of said contact plate and terminating in a contact finger projecting outwardly of the panel face; the other unit including a similar panel and contact set inserted therein in reverse and opposed relation to said first unit whereby the contact fingers of one unit slidably frictionally engage the contact plates of the other on axially moving the panels thereof face-toface.

8. A contact assembly for a separable multi-contact connector comprising a pair of interengageable units; one of said units including a panel having a plurality of apertures and a set of contact elements inserted therein, one wall of each aperture symmetrically converging inwardly from the opposite faces of the panel to a reduced central section, each contact element including a resiliently supported pressure plate abutted against a converging side of said wall, a contact plate extending at one side of said aperture and having a lateral end portion latched over the aperture edge to maintain said pressure plate in position, a spring arm extending from said pressure plate at the other side of said aperture and biased thereby toward the plane of said contact plate, said spring arm terminating in a contact finger projecting outwardly of the panel face; the other unit including a similar panel and contact set inserted therein in reverse and opposed relation to said first unit 1 1 whereby the contact fingers of one unit slidably frictionally engage the contact plates of the other on axially moving the panels thereof face-to-face; and means for reversibly mounting the panels in the units.

9. For use in a unit in a contact assembly of a connector, a panel of insulating material having a main body portion, a plurality of generally rectangular apertures extending through said body portion for receiving a set of contacts, one wall of each of said apertures symmetrically converging inwardly in planes from both faces of said panel to define stop shoulder means in said aperture for engaging complementary parts of a contact on insertion from either face of the panel, the other walls substantially defining transverse planes relative to said faces.

10. A panel as set forth in claim 9 wherein the converging portions of said Wall each extend approximately 12 one-third the length and inclined at an angle of substantially 15 to the axis of the aperture.

References Cited in the file of this patent 'UNITED STATES PATENTS 1,747,896 Gates Feb. 18, 1930 1,841,736 'Jones Ian. 19, 1932 2,111,118 Lake Mar. 15, 1938 2,318,648 Penfold May 11, 1943 2,724,093 Preston Nov. 15, 1955 2,846,672 Hennessey Aug. 5, 1958 FOREIGN PATENTS 808,723 Germany July 19, 1951 1,011,030 Germany June 27, 1957 

